1. Technical Field
The present disclosure relates to a field emission electronic device.
2. Description of Related Art
Field emission electronic devices provide many advantages such as low power consumption, fast response speed, and high resolution. Therefore, they are being actively developed.
Carbon nanotubes (CNTs) produced by means of arc discharge between graphite rods were first discovered and reported in an article by Sumio Iijima, entitled “Helical Microtubules of Graphitic Carbon” (Nature, Vol. 354, Nov. 7, 1991, pp. 56-58). CNTs also feature extremely high electrical conductivity, very small diameters (much less than 100 nanometers), large aspect ratios (i.e. length/diameter ratios greater than 1000), and a tip-surface area near the theoretical limit (the smaller the tip-surface area, the more concentrated the electric field, and the greater the field enhancement factor). These features tend to make CNTs ideal candidates for electron emitters.
A carbon nanotube wire is provided as an electron emitter of a field emission electronic device. The carbon nanotube wire includes a first end and a second end opposite to the first end. The first end of the carbon nanotube wire may be connected to a conductive base. The second end of the carbon nanotube wire extends from the conductive base along a direction away from the conductive base. The second end of the carbon nanotube wire is used as an electron emission portion. A number of electrons can be emitted from the second end of the carbon nanotube wire. However a cross section of the second end of the carbon nanotube wire is planar because the carbon nanotube wire is formed by cutting a longer carbon nanotube wire. Therefore, the field emission characteristic of the carbon nanotube wire is bad, and the field emission characteristic of field emission electronic device is also bad.
What is needed, therefore, is to provide a field emission electronic device having improved field emission characteristics.